/*
 * MIT License
 *
 * Copyright (c) 2024 org.zzz (https://gitee.com/frostforest)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package org.zzz.pcdc;

import javax.sql.DataSource;
import java.sql.*;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.LockSupport;

import static org.zzz.pcdc.PcdcUtils.stripLineByLine;

class PcdcSequence {
    final DataSource dataSource;

    PcdcSequence(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    private int generateWorkerId() throws SQLException {
        String insertRollback = stripLineByLine("""
                INSERT INTO `zzz_pcdc_sequence` () VALUES ()
                """);
        try (Connection conn = dataSource.getConnection()) {
            conn.setAutoCommit(false);
            try (PreparedStatement insertRollbackStmt = conn.prepareStatement(
                    insertRollback, Statement.RETURN_GENERATED_KEYS)) {
                insertRollbackStmt.executeUpdate();
                try (ResultSet rs = insertRollbackStmt.getGeneratedKeys()) {
                    if (rs.next()) {
                        Long nextValue = rs.getLong(1);
                        return nextValue.intValue();
                    }
                    throw new RuntimeException("Failed to get worker id");
                } finally {
                    conn.rollback();
                }
            }
        }
    }

    public int getWorkerId() {
        RuntimeException exception = new RuntimeException("Failed to generate WorkerID");
        Exception cause = null;
        for (int i = 0; i < 3; i++) {
            try {
                int workerId = generateWorkerId();
                return workerId;
            } catch (Exception e) {
                if (cause != null) {
                    e.addSuppressed(cause);
                }
                cause = e;
                LockSupport.parkNanos(TimeUnit.MILLISECONDS.toNanos(200));
            }
        }
        exception.addSuppressed(cause);
        throw exception;
    }
}
